A study in the USA detected Vitamin D insufficiency in 77.2% of patients presenting to their primary care doctor with fatigue and significant improvements in fatigue symptoms were achieved with normalisation.

Nowak A, Boesch L, Andres E, Battegay E, Hornemann T, Schmid C, et al

A study in the UK demonstrated that Vitamin D levels in non-professional athletes and healthy adults were significantly declined during the winter months.

Close GL, Russell J, Cobley JN, Owens DJ, Wilson G, Gregson W, et al.

It is estimated that approximately 50% of people worldwide have insufficient levels of Vitamin D and thankfully it is an easily accessible supplement. So, why should you take Vitamin D? The vast majority of people you meet will be able to tell you it’s “good for you”, but what exactly is it, why do I need it, and where can I find it? Vitamin D is often referred to as the Sunshine Vitamin because the primary source of this important compound is from sunlight exposure in adults. In fact, it is understood that at least 80% of our Vitamin D production is thanks to ultraviolet B radiation from the sun. A brief description involves the photo-conversion of 7-dehydrocholesterol to previtamin D and more, but the key point, which you may have already realised, is that we don’t always get the sun exposure we might like, particularly in winter months. The remaining 10-20% of Vitamin D in adults is made up by limited nutritional sources such as oily fish, egg yolks, and fortified foods such as soy milk and some cereals.